title: Neural evidence for individual and cultural variability in the social comparison effect.
abstract: Although several studies have investigated the neural mechanism of social comparison, it remains unclear whether and how cultural membership, particularly independent versus interdependent cultures, may differentially shape the neural processes underlying social comparison. In the present functional magnetic resonance imaging (fMRI) study, we examined the behaviors and neural response patterns of Korean (i.e., interdependent culture) and American (i.e., independent culture) participants while performing a financial gambling task simultaneously and independently with a partner. Upon seeing the partner's income, greater modulation of the activity in the ventral striatum (VS) and the ventromedial prefrontal cortex (vmPFC) by relative gain was observed in Korean than American participants, suggesting greater sensitivity of Koreans toward social comparison. The strength of functional connectivity between the VS and the vmPFC predicted individual variability in the degree to which participants' decisions were affected by relative incomes. Additional model-based fMRI analysis further confirmed the primary role of the vmPFC in biasing decisions based on relative incomes. In summary, the present study provides the first neural evidence for decision biases due to social comparison and their individual and cultural variations.
authors.affiliation: Laboratory of Social and Decision Neuroscience, Department of Psychology, and Department of Brain and Cognitive Engineering, Korea University, Seoul 136-701, South Korea, and Department of Psychology, Seoul National University, Seoul 151-742, South Korea.
authors.forename: Pyungwon
authors.initials: P
authors.lastname: Kang
authors.forename: Yongsil
authors.initials: Y
authors.lastname: Lee
authors.forename: Incheol
authors.initials: I
authors.lastname: Choi
authors.forename: Hackjin
authors.initials: H
authors.lastname: Kim
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D003469:Culture; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging